1. Field of the Invention
The present invention relates to a transparent electrode including a graphene sheet, and a display and a solar cell respectively including the electrode, and more particularly, to a transparent electrode having improved electrical and physical characteristics by employing a large-area graphene sheet having a desired thickness, and a display and a solar cell respectively including the transparent electrode.
2. Description of the Related Art
In general, display devices and solar cells which transmit light to form images or generate electric power include transparent electrodes as an essential element. Indium tin oxide (ITO) is widely used for a transparent electrode. However, with increased utilization and cost of ITO, the use of ITO is becoming uneconomical. Also, when a transparent electrode formed of ITO is bent, cracks occur therein, and thus the electrode's resistance increases.
Accordingly, the use of ITO electrodes may cause quality deterioration in flexible devices, and thus there is a need to develop a novel transparent electrode that can be used in flexible devices, for example, a transparent electrode including a carbon nanotube. A transparent electrode including a carbon nanotube can be used in a wide variety of devices, such as liquid crystal devices (LCDs), organic light emitting display devices (OLEDs), electronic paper like displays, or solar cells. However, carbon nanotubes have a very low yield when are purified after synthesis. Carbon nanotubes exhibit different metallic and semiconducting characteristics according to their chirality and diameter. Furthermore, since carbon nanotubes having identical semiconducting characteristics have different energy band gaps, carbon nanotubes are required to be separated from each other in order to obtain desired semiconducting or metallic characteristics. However, separating single wall carbon nanotubes is not a simple process.